Решение:
from django.db.models import Q
article = get_object_or_404(Article, slug=slug)
for tag in article.tag.replace(' ', '')split(','):
try:
query = query | Q(tag__icontains = tag)
except NameError:
query = Q(tag_icontains = tag)
othet = Article.objects.exclude(id = article.id).filter(query)
return ....
by Nick Kyrnoj
